Re: [Gluster-devel] query about why glustershd can not afr_selfheal_recreate_entry because of "afr: Prevent null gfids in self-heal entry re-creation"

[Ravishankar N]

On 01/16/2018 02:22 PM, Lian, George (NSB - CN/Hangzhou) wrote:

Hi,

Thanks a lots for your update.

I would like try to introduce more detail for which the issue came from.

This issue is came from a test case in our team, it is the step like 
the following:

1)Setup a glusterfs ENV with replicate 2 storage server nodes and 2 
client nodes

2)Generate a split-brain file , sn-0 is normal, sn-1 is dirty.

Hi , sorry I did not understand the test case. What type of split-brain 
did you create? (data/metadata or gfid or file type mismatch)?

3)Delete the directory before heal begin  (in this phase, the normal 
correct file in sn-0 is deleted by “rm” command , dirty file is still 
there )

Delete from the backend brick directly?

4)After that, the self-heal process will always be failure with the 
log which attached in last mail

Maybe you can write a script or a .t file (like the ones in 
https://github.com/gluster/glusterfs/tree/master/tests/basic/afr) so 
that your test can be understood unambiguously.

Also attach some command output FYI.

From my understand , the Glusterfs maybe can’t handle the split-brain 
file in this case, could you share your comments and confirm whether 
do some enhancement for this case or not?

If you create a split-brain in gluster, self-heal cannot heal it. You 
need to resolve it using one of the methods listed in 
https://docs.gluster.org/en/latest/Troubleshooting/resolving-splitbrain/#heal-info-and-split-brain-resolution

Thanks,
Ravi

/_rm -rf /mnt/export/testdir rm: cannot remove 
'/mnt/export/testdir/test file': No data available_//__/

/__/

/__/

/_[root@sn-1:/root]_/

/_# ls -l /mnt/export/testdir/_/

/_ls: cannot access '/mnt/export/testdir/IORFILE_82_2': No data 
available_/

/_total 0_/

/_-????????? ? ? ? ?            ? test_file_/

/__/

/_[root@sn-1:/root]_/

/_# getfattr -m . -d -e hex /mnt/bricks/export/brick/testdir/_/

/_getfattr: Removing leading '/' from absolute path names_/

/_# file: mnt/bricks/export/brick/testdir/_/

/_trusted.afr.dirty=0x000000000000000000000001_/

/_trusted.afr.export-client-0=0x000000000000000000000054_/

/_trusted.gfid=0xb217d6af49024f189a69e0ccf5207572_/

/_trusted.glusterfs.dht=0x000000010000000000000000ffffffff_/

/__/

/_[root@sn-0:/var/log/glusterfs]_/

/_#  getfattr -m . -d -e hex /mnt/bricks/export/brick/testdir/_/

/_getfattr: Removing leading '/' from absolute path names_/

/_# file: mnt/bricks/export/brick/testdir/_/

/_trusted.gfid=0xb217d6af49024f189a69e0ccf5207572_/

/_trusted.glusterfs.dht=0x000000010000000000000000ffffffff_/

/__/

Best Regards

George

*From:*gluster-devel-boun...@gluster.org 
[mailto:gluster-devel-boun...@gluster.org] *On Behalf Of *Ravishankar N
*Sent:* Tuesday, January 16, 2018 1:44 PM
*To:* Zhou, Cynthia (NSB - CN/Hangzhou) 
<cynthia.z...@nokia-sbell.com>; Gluster Devel <gluster-devel@gluster.org>
*Subject:* Re: [Gluster-devel] query about why glustershd can not 
afr_selfheal_recreate_entry because of "afr: Prevent null gfids in 
self-heal entry re-creation"

+ gluster-devel

On 01/15/2018 01:41 PM, Zhou, Cynthia (NSB - CN/Hangzhou) wrote:

    Hi glusterfs expert,

            Good day,

            When I do some test about glusterfs self-heal I find
    following prints showing when dir/file type get error it cannot
    get self-healed.

    *Could you help to check if it is an expected behavior ? because I
    find the code change **https://review.gluster.org/#/c/17981/**add
    check for iatt->ia_type,  so what if a file’s ia_type get
    corrupted ? in this case it should not get self-healed* ?


Yes, without knowing the ia-type , afr_selfheal_recreate_entry () 
cannot decide what type of FOP to do (mkdir/link/mknod ) to create the 
appropriate file on the sink. You would need to find out why the 
source brick is not returning valid ia_type. i.e. why 
replies[source].poststat is not valid.
Thanks,
Ravi


    Thanks!

    //////////////////heal info output////////////////////////////

    [root@sn-0:/home/robot]

    # gluster v heal export info

    Brick sn-0.local:/mnt/bricks/export/brick

    Status: Connected

    Number of entries: 0

    Brick sn-1.local:/mnt/bricks/export/brick

    /testdir - Is in split-brain

    Status: Connected

    Number of entries: 1

    //////////////////////////////////////////sn-1 glustershd
    log///////////////////////////////////////////////////

    [2018-01-15 03:53:40.011422] I [MSGID: 108026]
    [afr-self-heal-entry.c:887:afr_selfheal_entry_do]
    0-export-replicate-0: performing entry selfheal on
    b217d6af-4902-4f18-9a69-e0ccf5207572

    [2018-01-15 03:53:40.013994] W [MSGID: 114031]
    [client-rpc-fops.c:2860:client3_3_lookup_cbk] 0-export-client-1:
    remote operation failed. Path: (null)
    (00000000-0000-0000-0000-000000000000) [No data available]

    [2018-01-15 03:53:40.014025] E [MSGID: 108037]
    [afr-self-heal-entry.c:92:afr_selfheal_recreate_entry]
    0-export-replicate-0: Invalid ia_type (0) or
    gfid(00000000-0000-0000-0000-000000000000). source brick=1,
    pargfid=00000000-0000-0000-0000-000000000000, name=IORFILE_82_2

    //////////////////////////////////////gdb attached to sn-1
    glustershd/////////////////////////////////////////////

    root@sn-1:/var/log/glusterfs]

    # gdb attach 2191

    GNU gdb (GDB) 8.0.1

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    License GPLv3+: GNU GPL version 3 or later
    <http://gnu.org/licenses/gpl.html>

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    copying"

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    Type "show configuration" for configuration details.

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    Type "apropos word" to search for commands related to "word"...

    attach: No such file or directory.

    Attaching to process 2191

    [New LWP 2192]

    [New LWP 2193]

    [New LWP 2194]

    [New LWP 2195]

    [New LWP 2196]

    [New LWP 2197]

    [New LWP 2239]

    [New LWP 2241]

    [New LWP 2243]

    [New LWP 2245]

    [New LWP 2247]

    [Thread debugging using libthread_db enabled]

    Using host libthread_db library "/lib64/libthread_db.so.1".

    0x00007f90aca037bd in __pthread_join (threadid=140259279345408,
    thread_return=0x0) at pthread_join.c:90

    90      pthread_join.c: No such file or directory.

    (gdb) break afr_selfheal_recreate_entry

    Breakpoint 1 at 0x7f90a3b56dec: file afr-self-heal-entry.c, line 73.

    (gdb) c

    Continuing.

    [Switching to Thread 0x7f90a1b8e700 (LWP 2241)]

    Thread 9 "glustershdheal" hit Breakpoint 1,
    afr_selfheal_recreate_entry (frame=0x7f90980018d0, dst=0,
    source=1, sources=0x7f90a1b8ceb0 "", dir=0x7f9098011940,
    name=0x7f909c015d48 "IORFILE_82_2",

        inode=0x7f9098001bd0, replies=0x7f90a1b8c890) at
    afr-self-heal-entry.c:73

    73      afr-self-heal-entry.c: No such file or directory.

    (gdb) n

    74      in afr-self-heal-entry.c

    (gdb) n

    75      in afr-self-heal-entry.c

    (gdb) n

    76      in afr-self-heal-entry.c

    (gdb) n

    77      in afr-self-heal-entry.c

    (gdb) n

    78      in afr-self-heal-entry.c

    (gdb) n

    79      in afr-self-heal-entry.c

    (gdb) n

    80      in afr-self-heal-entry.c

    (gdb) n

    81      in afr-self-heal-entry.c

    (gdb) n

    82      in afr-self-heal-entry.c

    (gdb) n

    83      in afr-self-heal-entry.c

    (gdb) n

    85      in afr-self-heal-entry.c

    (gdb) n

    86      in afr-self-heal-entry.c

    (gdb) n

    87      in afr-self-heal-entry.c

    (gdb) print iatt->ia_type

    $1 = IA_INVAL

    (gdb) print gf_uuid_is_null(iatt->ia_gfid)

    $2 = 1

    (gdb) bt

    #0  afr_selfheal_recreate_entry (frame=0x7f90980018d0, dst=0,
    source=1, sources=0x7f90a1b8ceb0 "", dir=0x7f9098011940,
    name=0x7f909c015d48 "IORFILE_82_2", inode=0x7f9098001bd0,
    replies=0x7f90a1b8c890)

        at afr-self-heal-entry.c:87

    #1  0x00007f90a3b57d20 in __afr_selfheal_merge_dirent
    (frame=0x7f90980018d0, this=0x7f90a4024610, fd=0x7f9098413090,
    name=0x7f909c015d48 "IORFILE_82_2", inode=0x7f9098001bd0,

        sources=0x7f90a1b8ceb0 "", healed_sinks=0x7f90a1b8ce70
    "\001\001A\230\220\177", locked_on=0x7f90a1b8ce50
    "\001\001\270\241\220\177", replies=0x7f90a1b8c890) at
    afr-self-heal-entry.c:360

    #2  0x00007f90a3b57da5 in __afr_selfheal_entry_dirent
    (frame=0x7f90980018d0, this=0x7f90a4024610, fd=0x7f9098413090,
    name=0x7f909c015d48 "IORFILE_82_2", inode=0x7f9098001bd0, source=-1,

        sources=0x7f90a1b8ceb0 "", healed_sinks=0x7f90a1b8ce70
    "\001\001A\230\220\177", locked_on=0x7f90a1b8ce50
    "\001\001\270\241\220\177", replies=0x7f90a1b8c890) at
    afr-self-heal-entry.c:379

    #3  0x00007f90a3b5881f in afr_selfheal_entry_dirent
    (frame=0x7f90980018d0, this=0x7f90a4024610, fd=0x7f9098413090,
    name=0x7f909c015d48 "IORFILE_82_2", parent_idx_inode=0x0,
    subvol=0x7f90a4022240,

        full_crawl=_gf_true) at afr-self-heal-entry.c:610

    #4  0x00007f90a3b58da8 in afr_selfheal_entry_do_subvol
    (frame=0x7f90980110f0, this=0x7f90a4024610, fd=0x7f9098413090,
    child=1) at afr-self-heal-entry.c:742

    #5  0x00007f90a3b5953a in afr_selfheal_entry_do
    (frame=0x7f90980110f0, this=0x7f90a4024610, fd=0x7f9098413090,
    source=-1, sources=0x7f90a1b8d810 "",

        healed_sinks=0x7f90a1b8d7d0 "\001\001\270\241\220\177") at
    afr-self-heal-entry.c:908

    #6  0x00007f90a3b59b79 in __afr_selfheal_entry
    (frame=0x7f90980110f0, this=0x7f90a4024610, fd=0x7f9098413090,
    locked_on=0x7f90a1b8d920 "\001\001\\Z") at afr-self-heal-entry.c:1002

    #7  0x00007f90a3b5a051 in afr_selfheal_entry
    (frame=0x7f90980110f0, this=0x7f90a4024610, inode=0x7f9098011940)
    at afr-self-heal-entry.c:1112

    #8  0x00007f90a3b519b1 in afr_selfheal_do (frame=0x7f90980110f0,
    this=0x7f90a4024610, gfid=0x7f90a1b8db20
    "\262\027֯I\002O\030\232i\340\314\365 urP۸\241\220\177") at
    afr-self-heal-common.c:2459

    #9  0x00007f90a3b51aa7 in afr_selfheal (this=0x7f90a4024610,
    gfid=0x7f90a1b8db20 "\262\027֯I\002O\030\232i\340\314\365
    urP۸\241\220\177") at afr-self-heal-common.c:2500

    #10 0x00007f90a3b5cf1f in afr_shd_selfheal (healer=0x7f90a4033510,
    child=1, gfid=0x7f90a1b8db20 "\262\027֯I\002O\030\232i\340\314\365
    urP۸\241\220\177") at afr-self-heald.c:334

    #11 0x00007f90a3b5d2c8 in afr_shd_index_heal
    (subvol=0x7f90a4022240, entry=0x7f909c0169c0,
    parent=0x7f90a1b8dde0, data=0x7f90a4033510) at afr-self-heald.c:431

    #12 0x00007f90adc74654 in syncop_mt_dir_scan
    (frame=0x7f90a407b4f0, subvol=0x7f90a4022240, loc=0x7f90a1b8dde0,
    pid=-6, data=0x7f90a4033510, fn=0x7f90a3b5d17c <afr_shd_index_heal>,

        xdata=0x7f90a4002380, max_jobs=1, max_qlen=1024) at
    syncop-utils.c:407

    #13 0x00007f90a3b5d4e1 in afr_shd_index_sweep
    (healer=0x7f90a4033510, vgfid=0x7f90a3b84f38
    "glusterfs.xattrop_index_gfid") at afr-self-heald.c:481

    #14 0x00007f90a3b5d5bd in afr_shd_index_sweep_all
    (healer=0x7f90a4033510) at afr-self-heald.c:504

    #15 0x00007f90a3b5d894 in afr_shd_index_healer
    (data=0x7f90a4033510) at afr-self-heald.c:584

    #16 0x00007f90aca024a5 in start_thread (arg=0x7f90a1b8e700) at
    pthread_create.c:465

    #17 0x00007f90ac2e959f in clone () at
    ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

    (gdb)

    Best regards,
    *Cynthia **（周琳）*

    MBB SM HETRAN SW3 MATRIX

    Storage
    Mobile: +86 (0)18657188311


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